Corpus: Hepatic portal vein

The hepatic portal vein is a large vessel that carries oxygen-poor but nutrient-rich blood from the digestive organs to the liver.

The hepatic portal vein is located behind the pancreas and travels with the hepatic artery in the hepatoduodenal ligament toward the porta hepatis. It forms from the union of the superior mesenteric vein and the splenic vein, a convergence known as the confluence. Other tributary veins also join the portal vein along its course.

Once it enters the liver, the hepatic portal vein splits into two branches, each serving the right and left lobes of the liver. From there, it further divides into smaller branches that end in the hepatic sinusoids.

• Right gastric vein (from the stomach)
• Left gastric vein (from the stomach)
• Pyloric vein (from the pylorus)
• Superior mesenteric vein (from the small intestine)
• Inferior mesenteric vein (from the colon, flows into the splenic vein)
• Splenic vein (from the spleen)

Other smaller tributaries include the cystic vein (from the gallbladder) and the paraumbilical veins.

The hepatic portal vein is essential for transporting nutrient-rich blood from the gastrointestinal tract to the liver for processing. The liver metabolizes nutrients and detoxifies substances, ensuring that any absorbed toxins (such as ammonia) are processed before entering the systemic circulation. This system of blood flow is known as portal circulation.

Key pathological conditions affecting the portal vein include:

• Portal vein thrombosis
• Portal hypertension